1. Field of the Invention
The invention relates to a method for managing a communication network, in particular for generating tests at a higher-level network management center, and to a communication system for carrying out the method.
2. Description of the Related Art
In radio communication systems, information (for example speech, image information, or other data) are transmitted with the aid of electromagnetic waves via a radio interface between transmitting and receiving radio stations (base station and mobile station). The emission of the electromagnetic waves is performed in this case at carrier frequencies that lie in the frequency band provided for the respective system. In the case of GSM (Global System for Mobile Communication), the carrier frequencies lie in the region of 900, 1800 and 1900 MHz. Frequencies in the frequency band of approximately 2000 MHz are provided for future mobile radio networks using CDMA or TD/CDMA transmission methods via the radio interface, for example the UMTS (Universal Mobile Telecommunication System) or other third-generation system.
The principles of a general management network, which are also denoted as TMN principles (TMN: Telecommunications Management Network) define a plurality of management levels for the management of a communication system, for example a mobile communication system, each level having a dual function. In the managing system, each level apart from the lowermost has a manager function for the level situated therebelow. In the managed system, each level apart from the uppermost has an agent function for the next higher level.
In an object-oriented environment, there is a multiplicity of objects that constitute network resources with a specific functionality in each case. In the case of the object-oriented environment, such as exists typically between manager and agent in a mobile radio network, each agent functionality is appropriately provided by a specific object that is available as a managed object (or object instance MOI) of an object class.
The object is produced as the result of a modeling activity in which the parameters and boundary conditions, inter alia, are defined in addition to the functionality, and is known both to the manager and to the executive agent at the corresponding interface. In a mobile radio network, for example, the interface can be what is termed the O interface between an operation and maintenance center (OMC in FIG. 1) and a base station system (BSS).
An object instance of a specific managed class A, which is also denoted as managed object class, can include further object instances of the same or other classes. Such a relationship between object instances—not classes—is also denoted in the modeling as containment relationship.
A relationship between object classes which specifies that an object instance of a class is defined as a superior object for objects of another class, or can be so defined, is also denoted as name binding. A hierarchical assignment of objects in which the hierarchy is organized on the basis of name binding relationships is generally denoted as a naming tree.
In a telecommunication network, for example a mobile radio network, the network monitoring and control is usually performed in this case from two manager locations: on the one hand, centrally from an operation and maintenance center OMC, which corresponds to an element manager, and, on the other hand, on site by a local maintenance data terminal LMT (LMT: Local Maintenance Terminal) that can be connected to various network units. In a mobile radio network, for example, such network units are a base station subsystem BSC, a base station transceiver station BTSE (BTSE: Base Transceiver Station Equipment) that takes account of the hardware modeled or taken into account there, or a transcoder and rate adapter unit TRAU.
From an operational viewpoint, an overall telecommunication network managed by a service provider is subdivided into a plurality of network regions, as may also be seen from FIG. 1. Although the overall network includes hardware from various manufacturers, within each of these network regions both the network elements and the management systems set forth above are usually supplied from the same manufacturer, since the management at the operation and maintenance center OMC and at local maintenance data terminals must take account of all manufacturer-specific characteristics of the hardware. This includes, in particular, the tests of the functionality of individual components.
During the night, holidays and at the weekend, on the one hand the mobile radio network is monitored by a higher-level network management center that is usually denoted as network management center (NMC) since the regional operation and maintenance centers OMCs are unstaffed at these times. On the other hand, the interface between the network management center NMC and the regional operation and maintenance centers OMCs must remain manufacturer-independent, to permit a functional integration of manufacturer-specific network regions under a standard network management center NMC.
This independence of the OMC-NMC interface from manufacturer can arise in an object-oriented management environment through the exclusive use of what are termed functional object classes, in particular management object classes (functional-related MOC). The functional objects in this case model the network resources of a telecommunication network from a functional, manufacturer-independent point of view. By contrast therewith, the manufacturer-specific interface between the operation and maintenance center OMC and the network elements is also familiar with what are termed equipment-related management object classes (MOC) that differ from manufacturer to manufacturer. In this case, network elements are, for example, the base stations BSS, which are managed in a network region by an OMC.
To be able to react quickly to unforeseeable events, for example a failure of specific hardware components, the operator of the network management center NMC must be capable of starting appropriate tests. However, by contrast with operators at the operation and maintenance centers OMCs, the operators at the network management center have no system-specific knowledge of the equipment of a specific manufacturer. It is therefore impossible to carry out manufacturer-specific tests.